Vanadium redox flow batteries(VRFBs)are widely applied in energy storage systems(e.g.,wind energy,solar energy),while the poor activity of commonly used carbon-based electrode limits their large-scale application.In t...Vanadium redox flow batteries(VRFBs)are widely applied in energy storage systems(e.g.,wind energy,solar energy),while the poor activity of commonly used carbon-based electrode limits their large-scale application.In this study,the graphene modified carbon felt(G/CF)with a large area of 20 cm×20 cm has been successfully prepared by a chemical vapor deposition(CVD)strategy,achieving outstanding electrocatalytic redox reversibility of the VRFBs.The decorating graphene can provide abundant active sites for the vanadium redox reactions.Compared with the pristine carbon felt(CF)electrode,the G/CF composite electrode possesses more defective sites on surface,which enhances activity toward VO^(2+)/VO^(2+)couple and electrochemical performances.For instance,such G/CF electrode delivered remarkable voltage efficiency(VE)of 88.4%and energy efficiency(EE)of 86.4%at 100 mA·cm^(-2),much higher than CF electrode by 2.1%and 3.78%,respectively.The long-term cycling stability of G/CF electrode was further investigated and a high retention value of 47.6%can be achieved over 600 cycles.It is demonstrated that this work develops a promising and effective strategy to synthesize the large size of carbon electrode with high performances for the next-generation VRFBs.展开更多
研究全钒液流电池的质子传导膜制备过程,提出高分子亲水/疏水相互作用诱导溶液相分离的成膜原理,进行制膜工艺放大,满足全钒液流电池的电堆制造与储能工程应用需要.突破现有＂离子交换＂传质机理的限制,利用电解液中不同价态钒离子与氢...研究全钒液流电池的质子传导膜制备过程,提出高分子亲水/疏水相互作用诱导溶液相分离的成膜原理,进行制膜工艺放大,满足全钒液流电池的电堆制造与储能工程应用需要.突破现有＂离子交换＂传质机理的限制,利用电解液中不同价态钒离子与氢离子相比,存在体积和荷电量的差异,通过离子＂筛分＂和＂静电排斥＂效应进行离子选择性渗透.制成孔径分布在4~7 nm的聚偏氟乙烯质子传导膜,电导率为3.5×10-2S·cm-1,爆破强度高于0.3 MPa,面积800 mm×900 mm.利用扩散实验测定膜对H＋/VO2＋离子选择性,选择性系数达到306.利用该质子传导膜组装的15 k W电堆,充电/放电循环性能稳定,电流密度达到100 m A·cm-2,在700多个循环过程电流效率为93%,能量效率超过72%,具备产业化应用前景.展开更多
Metal-organic framework(MOF)and its derivatives have low-cost,controllable structure,and good catalytic performance,which are often used in the electrochemical field.In this work,SnO_(2)in situ modified graphite felt(...Metal-organic framework(MOF)and its derivatives have low-cost,controllable structure,and good catalytic performance,which are often used in the electrochemical field.In this work,SnO_(2)in situ modified graphite felt(SnO_(2)/GF)is prepared by hydrothermal method then simple thermal treatment using Sn-based MOF(Sn-MOF)as precursor.SnO_(2)is uniformly and firmly distributed on the GF surface rather than the common agglomeration and poor bonding of metal oxides on carbon-based electrodes,providing stable active centers for the VO^(2+)/VO_(2)^(+)and V^(2+)/V^(3+)redox reactions.At250 mA·cm^(-2),the energy efficiency of the battery with SnO_(2)/GF remains at 63.2%,while the blank one has failed.The former battery,at 100 mA·cm^(-2),has higher energy efficiency and good cycle stability(over 200 cycles).The battery performance of this study is better than that of most previous report in metal oxide-related work.This work obtains high-performance composite electrode by simple treatment of MOF,which provides a reference for the application of MOF in vanadium redox flow battery.展开更多
Proton conductivity of proton exchange membranes(PEMs)strongly relies on microscopic morphology,which can be modulated by engineering the distribution of ionic groups.Herein,poly(arylene ether)s with densely distribut...Proton conductivity of proton exchange membranes(PEMs)strongly relies on microscopic morphology,which can be modulated by engineering the distribution of ionic groups.Herein,poly(arylene ether)s with densely distributed allyl functionalities are polymerized from a tetra-allyl bisphenol A monomer.The subsequent thiol-ene addition with sodium 3-mercapto-1-propanesulfonate yields comb-shaped sulfonated fluorinated poly(arylene ether)s(SFPAEs)with ion exchange capacities(lECs)ranging from 1.29 mmol·g^-1 to 1.78 mmol g^-1.These SFPAEs exhibit superior proton conductivity over the whole temperature range,which is attributed to the enhanced hydrophilic/hydrophobic phase separation as evidenced by small angle X-ray scattering characterizations.The SFPAE-4-40 with an IEC of 1.78 mmol·g^-1 shows the largest proton conductivity of 93 mS-crrr1 at room temperature under fully hydrated condition,higher than that of Nafion 212.Furthermore,the vanadium redox flow battery(VRFB)assembled with SFPAE-4-40 separator exhibits higher energy efficiency than the VRFB assembled with Nafion 212.展开更多
采用聚乙烯为基体,炭黑和石墨为导电填料,通过碳布做增强骨架,制备了钒电池三明治型导电塑料基复合双极板。结果表明双极板的最佳配方为:m(炭黑)∶m(石墨)=45∶15,总填料含量为60%。碳布的引入有效地提高了双极板的力学性能,尤其是弯曲...采用聚乙烯为基体,炭黑和石墨为导电填料,通过碳布做增强骨架,制备了钒电池三明治型导电塑料基复合双极板。结果表明双极板的最佳配方为:m(炭黑)∶m(石墨)=45∶15,总填料含量为60%。碳布的引入有效地提高了双极板的力学性能,尤其是弯曲疲劳寿命大幅提高。该双极板在100 m A/cm 2的电流密度下,电流效率为97%,电压效率达到82%,能量效率达到80%。展开更多
Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes...Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes(ICMs)that provide high ion selectivity,proton conductivity,and stability under rigorous condition.Herein,a‘side-chain-type’strategy has been employed to fabricate highly stable phenolphthalein-based cardo poly(arylene ether ketone)s(PAEKs)membrane with low area resistance(0.058Ωcm^(2)),in which flexible alkyl spacers effectively alleviated inductive withdrawing effect from terminal ion exchange groups thus enabling a stable backbone.The assembled VFBs based on PAEKs bearing pendent alkyl chain terminated with quaternary ammonium(Q-PPhEK)demonstrated an energy efficiency above 80%over 700 cycles at 160 mA/cm^(2).Such a remarkable results revealed that the side-chain-type strategy contributed to enhancing the ICMs stability in strong oxidizing environment,meanwhile,more interesting backbones would be woken with this design engaging in stable ICMs for VFBs.展开更多
基金the financial support from the 100 Talented Team of Hunan Province(XiangZu[2016]91)the“Huxiang high-level talents”program(Nos.2018RS3077,2019RS1007,and 2019RS1046)+1 种基金the National Natural Science Foundation of China(No.52002405)the Open Fund of National Engineering Laboratory of Highway Maintenance Technology(Changsha University of Science&Technology)(No.kfj170105).
文摘Vanadium redox flow batteries(VRFBs)are widely applied in energy storage systems(e.g.,wind energy,solar energy),while the poor activity of commonly used carbon-based electrode limits their large-scale application.In this study,the graphene modified carbon felt(G/CF)with a large area of 20 cm×20 cm has been successfully prepared by a chemical vapor deposition(CVD)strategy,achieving outstanding electrocatalytic redox reversibility of the VRFBs.The decorating graphene can provide abundant active sites for the vanadium redox reactions.Compared with the pristine carbon felt(CF)electrode,the G/CF composite electrode possesses more defective sites on surface,which enhances activity toward VO^(2+)/VO^(2+)couple and electrochemical performances.For instance,such G/CF electrode delivered remarkable voltage efficiency(VE)of 88.4%and energy efficiency(EE)of 86.4%at 100 mA·cm^(-2),much higher than CF electrode by 2.1%and 3.78%,respectively.The long-term cycling stability of G/CF electrode was further investigated and a high retention value of 47.6%can be achieved over 600 cycles.It is demonstrated that this work develops a promising and effective strategy to synthesize the large size of carbon electrode with high performances for the next-generation VRFBs.
文摘研究全钒液流电池的质子传导膜制备过程,提出高分子亲水/疏水相互作用诱导溶液相分离的成膜原理,进行制膜工艺放大,满足全钒液流电池的电堆制造与储能工程应用需要.突破现有＂离子交换＂传质机理的限制,利用电解液中不同价态钒离子与氢离子相比,存在体积和荷电量的差异,通过离子＂筛分＂和＂静电排斥＂效应进行离子选择性渗透.制成孔径分布在4~7 nm的聚偏氟乙烯质子传导膜,电导率为3.5×10-2S·cm-1,爆破强度高于0.3 MPa,面积800 mm×900 mm.利用扩散实验测定膜对H＋/VO2＋离子选择性,选择性系数达到306.利用该质子传导膜组装的15 k W电堆,充电/放电循环性能稳定,电流密度达到100 m A·cm-2,在700多个循环过程电流效率为93%,能量效率超过72%,具备产业化应用前景.
基金the National Natural Science Foundation of China(Nos.51872090 and 51772097)Hebei Natural Science Fund for Distinguished Young Scholar(No.E2019209433)+1 种基金the Youth Talent Program of Hebei Provincial Education Department(No.BJ2018020)the Natural Science Foundation of Hebei Province(No.E2020209151)。
文摘Metal-organic framework(MOF)and its derivatives have low-cost,controllable structure,and good catalytic performance,which are often used in the electrochemical field.In this work,SnO_(2)in situ modified graphite felt(SnO_(2)/GF)is prepared by hydrothermal method then simple thermal treatment using Sn-based MOF(Sn-MOF)as precursor.SnO_(2)is uniformly and firmly distributed on the GF surface rather than the common agglomeration and poor bonding of metal oxides on carbon-based electrodes,providing stable active centers for the VO^(2+)/VO_(2)^(+)and V^(2+)/V^(3+)redox reactions.At250 mA·cm^(-2),the energy efficiency of the battery with SnO_(2)/GF remains at 63.2%,while the blank one has failed.The former battery,at 100 mA·cm^(-2),has higher energy efficiency and good cycle stability(over 200 cycles).The battery performance of this study is better than that of most previous report in metal oxide-related work.This work obtains high-performance composite electrode by simple treatment of MOF,which provides a reference for the application of MOF in vanadium redox flow battery.
基金the National Natural Science Foundation of China(Nos.51873037 and 51503038).
文摘Proton conductivity of proton exchange membranes(PEMs)strongly relies on microscopic morphology,which can be modulated by engineering the distribution of ionic groups.Herein,poly(arylene ether)s with densely distributed allyl functionalities are polymerized from a tetra-allyl bisphenol A monomer.The subsequent thiol-ene addition with sodium 3-mercapto-1-propanesulfonate yields comb-shaped sulfonated fluorinated poly(arylene ether)s(SFPAEs)with ion exchange capacities(lECs)ranging from 1.29 mmol·g^-1 to 1.78 mmol g^-1.These SFPAEs exhibit superior proton conductivity over the whole temperature range,which is attributed to the enhanced hydrophilic/hydrophobic phase separation as evidenced by small angle X-ray scattering characterizations.The SFPAE-4-40 with an IEC of 1.78 mmol·g^-1 shows the largest proton conductivity of 93 mS-crrr1 at room temperature under fully hydrated condition,higher than that of Nafion 212.Furthermore,the vanadium redox flow battery(VRFB)assembled with SFPAE-4-40 separator exhibits higher energy efficiency than the VRFB assembled with Nafion 212.
文摘采用聚乙烯为基体,炭黑和石墨为导电填料,通过碳布做增强骨架,制备了钒电池三明治型导电塑料基复合双极板。结果表明双极板的最佳配方为:m(炭黑)∶m(石墨)=45∶15,总填料含量为60%。碳布的引入有效地提高了双极板的力学性能,尤其是弯曲疲劳寿命大幅提高。该双极板在100 m A/cm 2的电流密度下,电流效率为97%,电压效率达到82%,能量效率达到80%。
基金the financial support of the National Natural Science Foundation of China(Nos.22075276,U19A2016,U22B6012)CAS Strategic Leading Science&Technology Program(A)(No.XDA21070000)+2 种基金Dalian High Level Talent Innovation Support Program(No.2020RD05)the Development of Scientic and Technological Project of the Jilin Province(No.20210101126JC)International Partnership Program of Chinese Academy of Sciences(No.121421KYSB20210028)。
文摘Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes(ICMs)that provide high ion selectivity,proton conductivity,and stability under rigorous condition.Herein,a‘side-chain-type’strategy has been employed to fabricate highly stable phenolphthalein-based cardo poly(arylene ether ketone)s(PAEKs)membrane with low area resistance(0.058Ωcm^(2)),in which flexible alkyl spacers effectively alleviated inductive withdrawing effect from terminal ion exchange groups thus enabling a stable backbone.The assembled VFBs based on PAEKs bearing pendent alkyl chain terminated with quaternary ammonium(Q-PPhEK)demonstrated an energy efficiency above 80%over 700 cycles at 160 mA/cm^(2).Such a remarkable results revealed that the side-chain-type strategy contributed to enhancing the ICMs stability in strong oxidizing environment,meanwhile,more interesting backbones would be woken with this design engaging in stable ICMs for VFBs.
